In the past, sanitary napkins have been constructed using an absorbent element having a body-facing side for receiving body fluids and an undergarment-facing side which may be lined or treated to render it impervious to body fluids. Although these sanitary napkins have sufficient absorbent capacity to collect and contain menstrual discharge, they often fall short in protecting against leakage at their sides and ends. Such failure may be due to the lack of continuous contact between the perineal area and the absorbent pad. For example, sanitary napkins designed to be attached adhesively to an undergarment tend to shift and move in tandem with the undergarment in response to the wearer's activity. Also, the absorbent cores of these sanitary napkins are often made of wood pulp fluff, which permanently deforms under relatively light compressive loads. Consequently, during use, a space usually forms between the napkin and the perineal area of the user, causing viscous fluid to flow along the body and stain the back part of the undergarment without being absorbed by the pad.
Several artisans have attempted to provide better body contact by providing a raised center or profile on the body-facing side of the napkin. See Lassen et al., U.S. Pat. No. 4,673,403 ('403), Jun. 16, 1987; Lassen et al., U.S. Pat. No. 4,631,062 ('062), Dec. 23, 1986; Roeder, U.S. Pat. No. 4,623,341 ('341), Nov. 18, 1986; Lassen et al., U.S. Pat. No. 4,605,405 ('405), Aug. 12, 1986; DesMarais, U.S. Pat. No. 4,425,130, Jan. 10, 1984; Roehr, U.S. Pat. No. 3,183,909 ('909), May 18, 1965; and Jacks, U.S. Pat. No. 2,662,527, Dec. 15, 1953, which are hereby incorporated by reference.
Lassen '403 discloses an incontinent garment or feminine pad having a indicator thereon to aid in the proper placement of the pad onto the body of a wearer. The pad includes a raised profile for locating the pad with respect to fluid flow within the vestibule of the wearer.
Lassen '062 describes a labial pad having an anatomically comfortable configuration including a laterally upwardly directed projection flowing generally along the longitudal axis within the posterior region of the pad and a prominence near the distal end which extends toward and tapers to the proximal end.
Roeder '341 describes a combination sanitary napkin and interlabial pad which includes an absorbent layer which tapers at one end and which is designed to fold over onto itself to form a double layer with the top layer designed, due to its reduced width, to engage the labia of the user. The upper layer of the pad is moveable with respect to the bottom absorbent layer.
Lassen '405 discloses a sanitary napkin which is provided with a positioning strap in slidable contact with a low friction baffle which is attached to the bottom of the napkin. The contact between the positioning strap and the baffle is maintained by a retention strap attached to the napkin which encircles the positioning strap. The napkin is dynamically moveable during use.
DesMarais, discloses a compound sanitary napkin including a primary menstrual pad and a panty protector joined at their respective transverse ends. The two members are free to move relative to one another along essentially the entire common length.
Roehr '909 discloses a convertible sanitary napkin which can alternatively provide a traditional menstrual pad and a semi-internally worn variation.
Jacks, discloses a sanitary pad having a raised center portion for positioning within a women's vestibule.
While these products provide a better anatomical fit, there remains a need for a slimmer and more comfortable sanitary napkin capable of maintaining good body contact without sacrificing the convenience of attachment to the undergarment. There is also a need for a napkin design which substantially prevents both early failures and "body" failures attributed to poor fit without sacrificing comfort.